(Applicant's Abstract) The goal of CORE B is to provide high purity eosinophil (EOS) preparations and to perform a variety of assays to assess cell function when placed in the different environments of Projects II, III, IV and V. It will be the aim of this facility to: 1. Provide pure peripheral EOS from normal subjects and patients with allergic rhinitis or allergic asthma, to provide pure bronchoalveolar lavage (BAL) EOS following segmental bronchoprovocation with allergen (SBP-AG) or inhaled corticosteroid (ICS) withdrawal; 2. Provide pure rat peritoneal EOS from study animals in Project II; 3. Perform functional assessment of human and rat EOS biology; 4. Adapt current protocols to the requirements of each project; and 5. Teach functional protocols to personnel of Projects II-V or to perform techniques necessary for specific studies.